Typing mechanism



May 26, 1942 H. w. KLABUNDE 2,284,324 .l

TYPING MECHANISM vFiled July 18, 1940 Z 25C 27 26C f5 /f mz /4 3c 2c 2Q l; a ffy M i? flic/jl.

YIl

Il "9 `35 lNvENToR 37 BY fW//awza/e @ya i ATTO R N EY l Patented May 26, 1942 zaaien NWED STATES PATENT I. @FFE-QE 'rrPrNG MEcnANrsM HenryWilliam Klabunde, Cleveland," Ohio, Vassignor to American Telephone and Telegraph Company, a corporation of New York Application July 18, 1940, vSerial No. 346,133`

` iclaim.' (crisp-4o)v This invention relates to typing mechanisms of the kind used in keyboard operated typewriters, electrical typewriters, teletypewriters, etc.

In machines of this class a so-called type basket is usually provided in vwhich type bars are pivotally mounted and so arranged as to be swung upwardly to enable the type carried by the type bar to impinge against the platen in order to print the desired character. The pivotal ends yof the type bars are usually mounted in a socalled type bar segment. The type bar segment isa member arcuate in form and having radial slots therein, the pivotal ends of the type bars being mounted to swing in said slots about a suitable fulcruin rod which may likewise be arcuate in form. v

Where the typing machine is used to fill out printed forms it is common practice'to have v particles of paper, resulting from the punching operation which prepares the paper, fall off the printed forms during the printing operation. In so far as these foreign particles fall outwardly among the type bars and the operating mechanisms below the type bars, no particular` harm results as the particles sift through the mechanisms and land on the bottom of the machine. Unfortunately, however, many of the particles upon being dislodged from the paper during the typing operation fall into the slots of the type bar segment, thereby interfering with the proper pivotal action of the type bars. This has been particularly annoying with teletypewriters and has been the cause of considerable maintenance expense.

In accordance with the present invention itis proposed to overcome this difculty by mounting a guard over the typebar lsegmenty in such a position that it will catch the small particles of paper that fall from the platen and thus preventthem from falling into the slots of the type bar segment. Since the type Vbars when swung upward to strike the platen are in a substantially vertical position, the guard must be so formed as not to interfere with the operation of the type bars, and for this reason must have a width only great enough to cover the upper surface of the type bar segment. Interference between the .type bar and the guard may be further prevented by oifsetting the main arm of the type bar with respect to its pivotal point.

The invention will now be more fully understood from the ,following detailed description when read in connection with the accompanying drawing, Figure 1 of which is a perspective view of a portion of the type basket of the teletypewriter with non-essential parts broken away. Fig. 2 is a perspective view ofthe guard before it is curved and mounted into position upon the type bar segment. Fig. 3 is a perspective view of the guard curved to conform to the shape of the type bar segment and mounted in position beneath the plate which supports the ribbon guide. Fig. 4 is a plan View of thetype bar cage and type bar segment with the guard mounted in place. Fig. 5- is a view, partly in cross-section, showing the relationship of the type bars, the guard, and the platen. Fig. 6 is a front View of the platen showing how the printed forms are carried thereby, and Fig..'7 is v,a cross-sectionV showing a detail of the mounting of the guard,

the cross-section being taken along the plane the rear end is provided with a curved notch or recess for pivotal purposes, as will be described later. The rear end of each type bar also carries a toothed segment with the teeth arrangedl in an arc about the center of the notched portion of the type bar as shown in Fig. `5. The rear ends of the type bars are mountedin slots 31 of a type bar segment 39 (see Figs. 3 and '7). The type bar segment 3l? is arcuate in form as shown in Figs. 1 and 3 yand in its upper surface a longitudinal groove 32 mountedthefulcrum rod 3 3. The fulcrum rod 33 lies inthenotched portions at the rear of each of the type bars and forms a fulcrum about which the type bars may be swung during the typing operation.y v

In order to actuate the type bars, pull bars Ic, 2c, 3c, etc., are provided, one corresponding to each type bar as shown in Figs. 4 and 5. These pull bars are each provided with racks at the rear ends thereof (as shown at ld in Fig. 5 in connection with the pull bar Mc). As the pull is provided in which isbar is pulled forward, the rack engages the teeth at the rear end of the type bar and causes it to rotate about the fulcrum rod 33. This enables mounted just below the typing surface of the the type heads to strike the type ribbon 34 (see f Fig. 1) and force it against the surface of the platen 35 to thereby print a character upon the perforated paper form 36.V The perforations of the form 36 engage with the p ins 31 on the platen to keep the printed form properly registeredVV with respect to the platen'as the platen is advanced line by line during the printing operation.,-

shifted longitudinally in certain permutationsl and combinations, a row of notches will rbe brought into alignment beneath Vthe pullV barv which is to be operated. For simplicity the arrangement of the notches in the pull bar is not illustrated. When the five notches beneath a particular` pull bar are' in alignment, the pull bar drops into the notches, as shown in connection With the pull bar I4c` in Fig. 5, so that its shoulder I4e engages the pullbar bail 5D. The bail is moved forward at a proper time in the sequence of operations by a mechanism which is not shown and thereby pulls the pull bar forward against the tension of the spring I4g. The result is that the rack 14d engaging with the teeth at the rear end ofthe selected type bar I4 causes it to be swung'upward to print a character.

Upon a portion of the frame above the type bar segment30 a `plate5| is attached as shown in Fig. 1, andv this plate serves as a mounting for the ribbon guide `52. Asthe selected type bar swings upwardly against the ribbon, the type bar head Lpasses between the two elements of the type bar guide53 to insure that the type will always strike in afproper position on the platen. In this connection it will be noted that the vouter or type-carrying ends of the type Vbars are slightly bent sidewise by increasing amounts aswe pass from the two inner type heads I 4a and |5s outwardly in either direction. This is -necessary in order that the type head as it swings about the fulcrum rod 33 will arrive at its striking point in a vertical' position. The bending of the outer ends of the Ytype bars as above described is shown inFigA.

As has already been stated, the processv of punchirig'the marginal perforations in the paper forms such as36 (see Fig. 6) results in punchings and other small' particles ofpaper adhering to the forms and these particles become dislodged Yfrom the paper during the printing operation,

thereby falling down Vfrom the front surface of the 'platen 35 into the groove 32 in the type bar segment 30. From this groove the particles may work their way into the slots 3| in the type bar segment, and since the rear ends of the type bars pivot within these slots, the dislodged particles cause the moving parts to become jammed, thus resulting in service troubles. As will be seen clearly in Fig. 5, the type bar segment is platen. Consequently the dislodged particles are more apt to fall into the groove 32 and the associated slots unless some means is provided to prevent this action.

YIn order to prevent these paper particles from falling into the groove 32 and the associated slots, a guard or cover 60 is provided which may be formed by pressing, or molding, or cutting from a sheet of suitable material an element in the 4 Y form shown in Fig. 2. As will be clear, the guard 60 his perforated tabs 6I and 62 attached thereto 'for the purpose of securing the guard to the machine. `In order to mount it in place the guard is bent into a curved form as shown at 60 f in Fig. 3 so that its edge 63 will t into the narf row groove formed between the upper edge of the of theV plate 5|.

type bar segment V3l) and the lower curved edge See particularly Figs. 1 and 3. The guard is then held in place by means of screws 64 and 65 passing through the holesfin the tabs 6| and B2. As shown particularly in Fig. 7, the guard 6U closely overlies the longitudinal groove in type bar segment 30. Consequently any small particles of paper falling from the platen will be prevented from entering the groove 32 and the associated slots, but will instead fall down in the spaces between the type if desired, from any of a number of suitable y metals.

It will be obvious that the general principles herein disclosed may be embodied in many other organizations widely different from those illustrated without departing from the spirit of the invention as defined inl the following claim.

What is claimed is:

Y 'In a typing device, a platen for feeding paper, a type basket including an arcuate type bar segment, an arcuate-shaped support for a ribbon guide, 'said support beingso located above said type bar segment as to form an arcuate space between said segment and saidsupport, alongitudinal groove in said segment, a fulcrum rod in said groove, said groove being open upwardly to permit ready access to said fulcrum rod, transverse slots in said segment, a plurality of type bars so mounted in said slots that they can be swung about said fulcrum rod to strike the paper on said platen, and a removable guard of thin material and bent into an arcuate form so that its rear edge may be inserted into the space between'said type bar segment and said ribbon guide support, said guard covering the groove and slots in said type bar segmentto prevent particles-of paper falling from the platen and interfering with the operation of said type bars, said guard also having tabs attached to the rear edge thereof near its ends, said tabs extending rearwardly over said type bar segment on opposite sides of said ribbon guide support and being attached to said segment.

HENRY W. 

